A motor cyclist starts from the bottom of a slope of angle 45o and travels along the slope to jump clear of the valley AB shown in figure. The width of the valley is 160 m and the length of the slope is 160√2 m. The minimum velocity with which he should leave the bottom O, so that he can clear the valley, is (nearest to in m/s)
(a) 50
(b) 56
(c) 60
(d) 70
